Endometrial cancer (ECa) is the most common cancer diagnosed in women. Genetics can only account for 5-10% of ECa risk and the rest lies in hormonally and environmentally influences. Observational studies strongly support unopposed estrogen exposure including endocrine-active substance and its associated metabolic complications are linked to a higher risk of ECa in human. In rat studies, neonatal exposure to BPA affects the adult uterine response to hormone and induced uterotrophy, uterine hyperplasia and cancer. However, data on a more human relevant exposure regimen that involves a low-dose lifespan oral exposure is non-existent. Additionally, the molecular mechanisms underlying pathogenesis remains incompletely understood. This project aims to address these data gap gaps by assessing the impact of chronic low dose exposue to bisphenol A (BPA) on uterine hyperplasia and carcinogenesis by using a well controlled GLP platform. The goal is to identify BPA-driven early cancer risk markers to promote translation into public health policy. The specific aims will be as follows. In aim 1, the investigators will establish a dose-response curve between chronic BPA exposure and the development of uterine atypical hyperplasia or adenocarcinoma and to determine an effective dose of BPA that will induce uterine tumor and/or hyperplasia/dysplasia in 75% of the 2-year-old rat. In aim 2, the investigators will identify BPA-associated early ECa biomarkers using an Exploration Approach, which combines genome-wide methylation promoter array analysis and global transcriptome profiling, and a Knowledge-based Approach, which selects a set of genes whose methylation status was discovered and confirmed in another ongoing study. In aim 3, the investigators will seek to determine the time course of changes of the candidate genes confirmed in aim 2 to identify the BPA-driven early uterine cancer marker genes.